Solve the linear system below by substitution. $$\left\lbrace \begin{array}{rcr} y-3x & = & -3 \\ 5y-15x & = & -15 \end{array} \right.$$ If the answer is a line such as $y = x + 1$, enter $x = x$ and $y = x+1$. If there is no solution, enter DNE for both answers.

$x =$
$y =$